September Weather in Slane, Ireland

Last updated: March 17, 2025

In September, Slane, Ireland, experiences a blend of mild temperatures and notable humidity, creating a unique atmospheric charm. With a maximum of 23°C (73°F) and a comfortable average of 14°C (57°F), visitors can enjoy the pleasant weather, though the minimum can dip to 3°C (37°F) during the night. The month sees approximately 71 mm (2.8 in) of rainfall spread over 11 days, contributing to the lush, green landscapes that Ireland is famous for. With a humidity level hovering around 86%, the air feels fresh and invigorating, making September an ideal time for exploring the captivating scenery and rich history of Slane.

September Temperature in Slane

As September unfolds in Slane, Ireland, the temperatures begin to hint at the impending autumn, with a minimum of 3°C (37°F) and an average of 14°C (57°F). Daytime highs can reach up to 23°C (73°F), providing a pleasant warmth reminiscent of summer's tail end, yet the overall trend marks a noticeable drop compared to the preceding months. While August may have lingered in the warmth of summer with similar high temperatures, September stands as a bridge, blending the last remnants of summer with the refreshing coolness of fall. As the month progresses, visitors can expect crisp mornings and mild afternoons, making it a delightful time to explore the lush landscapes of this charming Irish locale.

September Weather in Slane: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in Slane, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends.
JanFebMarAprMayJunJulAugSepOctNovDec424345485358616057514644
Data source: Temperature data for Slane generated using information from the Copernicus Climate Change Service.
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The average of daily temperatures (24 hours) calculated across all days in the month.

September Precipitation in Slane

In September, Slane experiences a moderate level of precipitation, with an average of 71 mm (2.8 in) falling across approximately 11 days. This month typically bridges the gap between the wetter summer and the impending autumn, showcasing a drop from August's heavier rainfall of 104 mm (4.1 in). That said, September still holds on to the clouds, ensuring the landscape remains lush and vibrant. Compared to earlier months like January and April, which see considerably less rain, September maintains a balance that supports both the scenery and local agriculture. As autumn approaches, the rhythm of rainfall suggests a gradual transition, preparing Slane for the wetter months ahead.

September Precipitation Trends in Slane

The chart displays monthly precipitation patterns in Slane, with values for each month alongside September's data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how September's conditions compare to those of other months.
JanFebMarAprMayJunJulAugSepOctNovDec5079764564737310471768385
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Slane

In September, Slane, Ireland experiences a notable humidity level of 86%, aligning with the region’s generally high moisture levels throughout the year. This consistency is evident as the humidity fluctuates between 83% and 87% from May to October, revealing a strikingly stable climate. Interestingly, both January and February begin the year with slightly higher humidity at 85% and 86%, gradually showcasing a slight dip in the warmer months before peaking again in the fall. As summer transitions into autumn, September stands as a bridge, maintaining elevated humidity that enhances the lush landscapes and vibrant atmosphere Slane is known for.

September Average Humidity in Slane

This chart illustrates the average monthly humidity levels in Slane, with September's data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, allowing you to see how September's humidity levels compare to other months.
JanFebMarAprMayJunJulAugSepOctNovDec85%86%86%85%83%85%86%85%86%87%87%84%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Slane

In September, Slane, Ireland, experiences a moderate UV Index of 5, suggesting that while sun exposure is generally safe, precautions are advisable, particularly during peak hours. With a burn time of 30 minutes, it's essential to keep an eye on the sunlight intensity as the summer months transition into autumn. This month marks a slight decline from the high summer readings of 8 in July and June, and a decrease from 7 in August, illustrating a gradual shift in seasonal light. As daylight begins to wane, outdoor enthusiasts should remain mindful of their exposure, leveraging options like hats and sunscreen for added protection. To stay informed and plan your sun safety, check out the comprehensive insights at Slane UV Index.

Maximum UV Index Levels in Slane for September

The chart shows the monthly maximum UV Index (UVI) for Slane in September, representing the highest UV radiation level. The UVI measures the intensity of ultraviolet radiation from the sun, indicating the potential risk of sunburn and UV-related health issues.
JanFebMarAprMayJunJulAugSepOctNovDec124578875321
Data source: Slane September UVI data generated using information from the Copernicus Climate Change Service.

UV Risk Categories

  •  Extreme (11+): Avoid the sun, stay in shade.
  •  Very High (8-10): Limit sun exposure.
  •  High (6-7): Use SPF 30+ and protective clothing.
  •  Moderate (3-5): Midday shade recommended.
  •  Low (0-2): No protection needed.

September Sunshine in Slane

In September, the charming village of Slane, Ireland, basks in a delightful 288 hours of sunshine, marking the end of a sun-drenched summer. This month tends to showcase a gentle decline in daylight as autumn approaches, yet it remains a standout, significantly brighter than the dreary winter months ahead, like January's 80 hours and December's 91 hours. Interestingly, September's sunshine echoes the patterns seen in the preceding summer months, especially when compared to July and August, which boast 377 and 329 hours, respectively. As leaves start to turn and the air cools, this month serves as a beautiful transition, reminding us that while the sun starts to shy away, there’s still plenty of warmth to enjoy.

Monthly Sunshine Duration in Slane: September Highlighted

The September sunshine duration represents the total number of hours Slane experiences direct sunlight during the month of September, excluding cloudy or obstructed periods. This chart compares the sunshine duration of September with the other months of the year.
JanFebMarAprMayJunJulAugSepOctNovDec80h145h190h308h385h379h377h329h288h226h114h91h
Data source: Slane September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Slane During September

As September rolls into Slane, Ireland, the likelihood of enjoying sunny weather dips to just 20%. This marks a notable decrease compared to the more promising sunshine seen in April, which boasts a sunny forecast of 40%. While early summer months like May and July hover around the mid-20s percentage range, September's chance reflects a downward trend as the nation transitions into autumn. This gradual decline in sun-soaked days, persisting through October and November, underscores the increasing unpredictability of clear skies during this time of year, making the search for sunshine in Slane a bit of a challenge as cozy sweaters replace T-shirts.

Percentage of Sunny Days in September in Slane

The chart illustrates the percentage of sunny days in Slane throughout the year, with September highlighted. It highlights the variation in sunshine across each month and provides an overview of the typical frequency of sunny days, offering insights into how often Slane experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec29%20%19%40%33%22%28%22%20%18%25%19%
Data source: Slane September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Slane in September

As September rolls into Slane, Ireland, the days begin to subtly shorten, ushering in a transition that reflects the changing seasons. With 12 hours of daylight, September offers a perfect balance between the lingering warmth of summer and the cooler embrace of autumn. This month marks a gentle decline from the vibrant 16 hours enjoyed in June and July, gradually tapering off as the days grow shorter. The daylight duration dips further to 10 hours in October, signaling the approach of winter. Overall, September serves as a captivating bridge, where longer, sun-kissed evenings still glimmer before the shorter days of fall take hold, inviting locals and visitors alike to savor the fading summer light.

Average Daylight Hours in Slane for September

The chart illustrates the variation in daylight duration in Slane throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec8h 4m9h 48m11h 54m14h 3m15h 57m16h 57m16h 25m14h 42m12h 37m10h 29m8h 33m7h 31m
Data source: Slane daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Slane

In Slane, Ireland, the September wind carries a gentle breeze, averaging about 3.3 m/s (7 mph), making it one of the quieter months for wind speeds. This is relatively calm compared to the earlier months of the year, notably February, where gusts peak at 5.4 m/s (12 mph). The trend shows a gradual decline in wind speed leading into the summer, with July experiencing the lowest average at 2.6 m/s (6 mph). As autumn approaches, the winds begin to pick up again in October, returning to 4.3 m/s (10 mph). This natural ebb and flow of wind speeds reflects the changing seasons, setting the stage for the more blustery months ahead.

Average September Wind Speed in Slane

The chart displays monthly wind speed patterns in Slane, with values for each month shown alongside September's data, which is highlighted for easy comparison. It illustrates the average wind speed, offering insights into how September's wind conditions compare to the rest of the year.
JanFebMarAprMayJunJulAugSepOctNovDec4.15.44.43.23.63.52.63.23.3 m/s4.34.54.5
Data source: Slane September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Slane Compares to Other Months

The weather in Slane changes throughout the year, offering a unique experience in each season. Below is a month-by-month comparison of September's weather with other months, highlighting differences in temperature, precipitation, and other key factors. Click on each section to discover seasonal trends in Slane and find detailed weather information for every month.

September and January present contrasting weather conditions. In September, temperatures range from a minimum of 3°C (37°F) to a maximum of 23°C (73°F), with an average temperature of 14°C (57°F). The month experiences around 71 mm (2.8 in) of precipitation over 11 days, with humidity levels at 86%. In contrast, January sees colder temperatures, with a minimum of -4°C (25°F), an average of 6°C (43°F), and a maximum of 14°C (58°F). This winter month averages 50 mm (2.0 in) of precipitation over 9 days, maintaining a similar humidity level of 85%. For more details on January weather, you can check Slane weather in January.

September and February show distinct differences in weather patterns. In September, temperatures range from a mild 3°C (37°F) to a warm 23°C (73°F), with an average of 14°C (57°F). The month experiences 71 mm (2.8 in) of precipitation over approximately 11 days, while humidity remains high at 86%. In contrast, February brings colder conditions, with temperatures ranging from -3°C (27°F) to a maximum of 15°C (60°F) and an average of 6°C (44°F). This month sees slightly more precipitation at 79 mm (3.1 in) across about 15 days, maintaining the same humidity level of 86%. For more detailed insights into the February weather, you can visit Slane weather in February.

September and March showcase distinctly different weather patterns. In September, temperatures typically range from a mild 3°C (37°F) to a pleasant 23°C (73°F), with an average of 14°C (57°F). The month experiences considerable precipitation, totaling 71 mm (2.8 in) over about 11 days, with humidity levels consistently around 86%. In contrast, March sees cooler temperatures, with lows of -4°C (26°F) and a maximum of 17°C (63°F), averaging 7°C (45°F). Precipitation in March is slightly higher at 76 mm (3.0 in) over more frequent rainy days, totaling 15, while humidity remains stable at 86%. For a more detailed look at March conditions, visit Slane weather in March.

September and April present contrasting weather patterns, with September generally being warmer and more humid. In September, temperatures range from a minimum of 3°C (37°F) to a maximum of 23°C (73°F), averaging around 14°C (57°F). The month also sees higher precipitation levels, with about 71 mm (2.8 in) falling over 11 days, contributing to a humidity of 86%. In contrast, April has colder temperatures, with a minimum of -2°C (28°F) and a maximum of 20°C (69°F), averaging just 9°C (48°F). Precipitation is lower in April, totaling 44 mm (1.8 in) over 10 days, and the humidity stands slightly lower at 85%. For more insights on the weather in April, check out Slane weather in April.

When comparing the weather in September and May, we observe some interesting differences. September generally has milder temperatures, with an average of 14°C (57°F) and a maximum of 23°C (73°F), while May tends to be a bit cooler, averaging 12°C (53°F) and peaking at 24°C (75°F). Precipitation is relatively similar in both months, with September receiving 71 mm (2.8 in) over 11 days and May slightly less at 64 mm (2.5 in) over 12 days. Humidity levels are quite comparable as well, with September at 86% and May slightly lower at 83%. For more specific details about May weather, you can visit Slane weather in May.

September and June present a noticeable contrast in weather patterns. September tends to be cooler, with temperatures ranging from a minimum of 3°C (37°F) to a maximum of 23°C (73°F), while June enjoys slightly warmer conditions with temperatures peaking at 28°C (83°F). Both months experience comparable precipitation levels—71 mm (2.8 in) in September and 73 mm (2.9 in) in June—though June sees slightly more rainy days, with precipitation occurring on 14 days compared to 11 days in September. Additionally, the humidity levels are quite similar, with September at 86% and June slightly lower at 85%. For a more detailed look at June weather, you can explore Slane weather in June.

In comparing the weather between September and July, we can see distinct differences in temperature and precipitation patterns. September typically experiences cooler temperatures, with minimums around 3°C (37°F) and maximums reaching 23°C (73°F), averaging 14°C (57°F). In contrast, July is warmer, showcasing minimums of 8°C (46°F) and maximums peaking at 28°C (83°F), averaging 16°C (62°F). Both months have similar levels of precipitation, with September receiving 71 mm (2.8 in) over 11 days and July slightly more at 73 mm (2.9 in) over 13 days. Humidity remains consistent at 86% for both months. For a closer look at July's specific weather conditions, visit Slane weather in July.

In comparing the weather of September to that of August, we can see several notable differences. September tends to be cooler overall, with a minimum temperature of 3°C (37°F) compared to August's milder 7°C (44°F). Both months share the same maximum temperature of 23°C (73°F), but September's average temperature is slightly lower at 14°C (57°F) versus August's 16°C (60°F). Precipitation is more common in August, with 104 mm (4.1 in) falling over 17 days, while September sees less rain at 71 mm (2.8 in) over 11 days. Humidity levels are fairly similar, with September at 86% and August at 85%. For more detailed information about August weather, visit Slane weather in August.

September tends to be milder than October, with average temperatures ranging from a minimum of 3°C (37°F) to a maximum of 23°C (73°F). In contrast, October sees cooler temperatures, with a minimum of 1°C (33°F) and a maximum of 20°C (68°F). Both months experience significant precipitation, but October has slightly higher rainfall at 76 mm (3.0 in) over 13 days, compared to September's 71 mm (2.8 in) over 11 days. Additionally, the humidity levels are fairly similar, sitting at 86% in September and 87% in October. For more specific information on October conditions, you can refer to Slane weather in October.

September and November exhibit distinct weather patterns that reflect the transition from late summer to early winter. In September, temperatures range from a mild minimum of 3°C (37°F) to an average of 14°C (57°F), peaking at 23°C (73°F). The month sees a slight increase in precipitation with 71 mm (2.8 in) over 11 days, while humidity remains high at 86%.

In contrast, November brings cooler temperatures, dropping to a minimum of -2°C (28°F) and averaging around 8°C (47°F), with a maximum of 15°C (60°F). The month experiences slightly more precipitation, totaling 83 mm (3.3 in) over 14 days, while humidity remains constant at 86%. For a detailed look at November weather conditions, check out Slane weather in November.

In September, temperatures in Slane typically range from a mild minimum of 3°C (37°F) to a pleasant maximum of 23°C (73°F), with an average of 14°C (57°F). The month experiences moderate precipitation of 71 mm (2.8 in) over approximately 11 days, accompanied by high humidity at 86%. In contrast, December brings colder weather, with temperatures dipping to a minimum of -2°C (28°F) and peaking at a maximum of 13°C (56°F), averaging around 6°C (44°F). Precipitation slightly increases to 85 mm (3.4 in) over 14 days, while humidity remains relatively high at 84%. This notable shift signifies a transition from the mild, somewhat humid conditions of early autumn to the chillier, wetter atmosphere of winter. For more detailed information, you can check out Slane weather in December.

Compare Slane's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Slane

As September rolls in, Slane experiences a notable shift in its weather compared to the summer months. The days grow cooler, with average temperatures dipping to a pleasant 14°C (57°F), while humidity levels rise to a notable 86%, making the air feel a bit heavier. It's also a month where you're likely to encounter more rain, with precipitation recorded on 11 days and accumulating to 71 mm (2.8 in), laying the groundwork for the vibrant fall colors ahead. For a deeper look at Slane's climate throughout the year, explore Slane Climate.